The clinical laboratory plays a critical role in the assessment of atherosclerotic cardiovascular disease (ASCVD)9 risk. Since the 1970s, this laboratory assessment has been primarily through tests in the lipid panel, which included cholesterol, triglycerides (TG), and HDL cholesterol (HDL-C) based on fasting serum or plasma specimens. Until the advent of direct LDL cholesterol (LDL-C) tests approximately 20 years ago, LDL-C was almost exclusively estimated by the Friedewald equation (valid when...more

The interference of bilirubin in both kinetic alkaline picrate creatinine assays (Jaffe) and enzymatic creatinine assays has been known and described in the literature (1, 2). Bilirubin negatively interferes with the Jaffe method, leading to underestimation of creatinine concentrations. Oxidation of bilirubin to biliverdin in alkaline solutions decreases the absorbance of both the creatinine picrate complex and bilirubin at the absorbance peak of 510 nm and increases the absorbance of biliverdin...more

Background: Protein detection assays are invaluable tools in the field of biomarker discovery. However, only immunoassays are widely used and can measure 10–20 analytes per biosample. The novel SOMAmer-based assay uses nucleotide aptamer technology to measure over 1300 analytes per biosample. We compared the SOMAmer-based platform to traditional approaches to quantify analytes in a clinical setting with paired samples before and after cardiac surgery. Methods: In a substudy of the Translational ...more

A 28-year-old man with a history of opioid abuse, currently prescribed Suboxone® to manage his opioid use disorder, submitted a urine specimen for a drug screen to verify abstinence from illicit compounds and compliance with the prescribed medication. The specimen screened positive by immunoassay (IA) for oxycodone and buprenorphine. Based on these results, the physician requested confirmation testing by LC-MS/MS and requested help interpreting the results (Table 1). View this table: Table 1. Pa...more

An 85-year-old man with a medical history significant for monoclonal IgM kappa gammopathy (Waldenstrom macroglobulinemia) was being evaluated for malnutrition. The serum homocysteine concentration, performed with a spectrophotometric enzymatic method (Roche cobas c701; Roche Diagnostics), was extremely high at 105.8 μmol/L (Table 1). Results for other laboratory tests were unremarkable. View this table: Table 1. Relevant laboratory results for this patient. 1. What conditions can cause increases...more

Kidney disease is a major contributor to morbidity and mortality in the US, affecting 14% of the population. It is often referred to as a “silent epidemic” because the disease is often asymptomatic until the late stages and current clinical assays only detect it after a substantial portion of kidney capacity has been lost. As such, there is marked interest in kidney disease biomarkers that could identify the extent of kidney damage earlier in the pathological process. This may allow for interven...more

A 68-year-old man with a history of ischemic cardiomyopathy presented with decompensated heart failure and acute kidney injury. He was admitted to the coronary care unit for dopamine-assisted diuresis via a central line. Serum creatinine testing was performed using an enzymatic creatininase method (Roche cobas c701; Roche Diagnostics), revealing erratic creatinine concentrations …